Oxygen, carbon, sulfur and chlorine are examples of non-metal elements.

All non-metals have these properties in common:

• they are dull (not shiny)

• they are poor conductors of heat and electricity (they are insulators)

• they are weak and brittle (they easily break or shatter)

Most non-metals have these properties:

• they have a low density (they feel light for their size)

• they do not make a ringing sound when they are hit (they are not sonourous)

Eleven non-metals are gases at room temperature, including oxygen and chlorine.
One non-metal, bromine, is a liquid at room temperature.
The other non-metals are solids at room temperature, including carbon and sulfur.

Curious carbon

Carbon is a solid non-metal element. Pure carbon can exist in two very different forms - diamond and graphite. The table shows some differences between them.

Diamond	Graphite
transparent and colourless	opaque and black
hard	soft

Diamond is the hardest natural substance on Earth, but it is also very brittle and will shatter if hit with a hammer.

Graphite is unusual because it is a non-metal that conducts electricity.

Diamonds are used in jewellery